1. Field of the Invention
The present invention relates to a magnetic recording medium for use in, e.g., a hard disk apparatus using the magnetic recording technique and, more particularly, to a magnetic recording medium having a magnetic recording layer so patterned that magnetic structures such as adjacent tracks are physically separated, a method of manufacturing the same, and a magnetic recording/reproduction apparatus using the same.
2. Description of the Related Art
As the capacity of a magnetic recording apparatus increases, the track density of the apparatus also increases together with its linear bit density.
As described in, e.g., Jpn. Pat. Appln. KOKAI Publication No. 3-142707, a so-called patterned medium is a magnetic recording medium having, on its surface, an array of magnetic structures corresponding to 1 bit of recording information.
This patterned medium is attracting attention because mutual interference between bits can be reduced and ultra-high-density recording can be performed by forming the magnetic structures by using materials having different magnetic properties.
The magnetic recording layer of the patterned medium is generally patterned using the photolithography technique. For example, after a magnetic recording layer and carbon protective layer are formed on a substrate, a photoresist is formed by coating, and this photoresist is exposed and developed to form a photoresist pattern corresponding to the array of the magnetic structures described above. This photoresist pattern is used as a mask to etch the magnetic recording layer and carbon protective layer. After that, the photoresist pattern is removed by using oxygen plasma etching or the like, thereby obtaining a patterned magnetic recording layer.
When exposed to an oxygen plasma, however, the carbon protective layer is readily removed, and the surface of the magnetic recording layer is oxidized. This degrades the electromagnetic conversion characteristics of the magnetic recording layer.